Functional expression of mechanosensitive two-pore domain potassium channel in human bladder carcinoma cells.
- Author:
Kyung Sun PARK
1
;
Yangmi KIM
Author Information
1. Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790-784, Korea.
- Publication Type:Original Article
- Keywords:
two-pore K+ channel;
TREK1;
bladder cancer 253J cell;
patch clamp;
single channel recording
- MeSH:
Acidosis;
Anoxia;
Apoptosis;
Cell Transformation, Neoplastic;
Fatty Acids, Nonesterified;
Fatty Acids, Unsaturated;
Humans*;
Hydrogen-Ion Concentration;
Male;
Membranes;
Neurotransmitter Agents;
Patch-Clamp Techniques;
Potassium Channels*;
Potassium*;
Smoke;
Smoking;
Tetraethylammonium;
Urinary Bladder Neoplasms;
Urinary Bladder*
- From:Journal of Biomedical Research
2013;14(2):71-76
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Bladder cancer is a common cancer in smoking men and may correlate with mechanosensitive potassium channels because the urinary bladder is a stretch sensing organ. Two-pore K+ channels (K2P), such as TASK3 and TREK1, have recently been shown to play a critical role in both cell apoptosis and tumorigenesis. Of the channels, TREK1 can be activated by many physiological stimuli, including polyunsaturated fatty acids, and intracellular pH, hypoxia, and neurotransmitters. Here we attempted to determine whether TREK1 is functionally expressed in bladder cancer 253J cells. K2P channels, including TREK1, TREK2, TASK1, TASK3, and TWIK1, were quantified in cultured human bladder cancer 253J cells using real time quantitative RT-PCR (qRT-PCR) analysis. Among them, TREK1-like channel was recorded at a single channel level using the patch-clamp technique. The TREKl-like channel, with single-channel conductance of ~90 pS at -80 mV, was recorded in symmetrical 150 mM KCl using an excised inside-out patch configuration. The current-voltage relationships were linear and were insensitive to tetraethylammonium. The channel was activated by membrane stretch, free fatty acids, and intracellular acidosis. These results with electrophysiological properties resemble to those of K2P channel, for instance, TREK1. Therefore, we conclude that TREK1 channel is functionally present in bladder cancer 253J cells.
